Not Applicable
Not Applicable
1. Field of the Invention
The present invention is in the field of railroad switching devices, namely the equipment which is used to displace railroad switch points. More specifically, the invention refers to a switching device for use with interconnected railroad switch points.
2. Background Art
A railroad switch point consists of tapered rail sections which are capable of being selectively displaced between two different positions at a rail switch and then locked in the selected position, in order to facilitate the desired routing of a train passing through the switch. The two switch points are typically displaced by rods extending from an assembly which is referred to herein as a xe2x80x9cswitch machinexe2x80x9d. Inside the switch machine the rods are usually connected to a motive mechanism which provides reciprocating rectilinear motion, controlled by a power unit which is usually placed to one side of the rails.
Such a device is described in Italian Patent No. IT1246656, to the inventor herein. The device described in that patent operates switch points which are independent, or disconnected, from each other, and it is not applicable to the problem of operating switch points of the interconnected type, i.e. of switch points connected to each other by transverse bars. Switch machines of the interconnected type are shown, for example, in U.S. Pat. Nos. 5,806,809 and 6,149,106.
Among the features of the present invention is the provision of an improved switch machine for the selective displacement of interconnected switch points. A second feature of the present invention is a highly reliable switch machine mechanism. Further features of the device disclosed herein include combining the switch point movement and switch point locking functions into a single mechanism to reduce mechanical complexity, enclosing the mechanism in a weather-proof housing, incorporating sensors and other electrical control components in the housing and locating the housing and operating assembly beneath the switch points and the associated rails.
More particularly, the present invention provides a switch machine for operating a switch having switch points interconnected by one or more transverse bars. The switch includes a fixed housing with an upper plate and a lower guide fixed therein. Two operating rods extend from either side of the fixed housing to the movable switch points, with the rods being capable of longitudinally sliding with respect to the fixed upper plate. A skate inside the housing is capable of sliding with respect to the fixed lower guide. An intermediate shift assembly is mounted to the skate for movement with respect to the fixed lower guide. A control rod is provided to selectively attach to the intermediate shift assembly to displace or stroke the intermediate shift assembly in opposite directions between two end points of the stroke. The machine also includes a first engagement mechanism for selectively engaging the operating rods to the fixed upper plate or to the skate to selectively move the switch points, and a second engagement mechanism for selectively engaging the intermediate shift assembly to the control rod and/or to the fixed lower guide to selectively lock the operating rods and the switch points in a desired position.
The novel features of this invention, as well as the invention itself, will be best understood from the attached drawings, taken along with the following description, in which similar reference characters refer to similar parts, and in which: